A high-performance ultraviolet photoconductive detector based on a ZnO film grown by RF sputtering

A high-performance metal-semiconductor-metal (MSM) ultraviolet photodetector was fabricated based on a ZnO film with Al interdigitated (IDT) electrodes. A c-axis-oriented ZnO film was grown on a SiO ₂/Si (100) substrate at room temperature by a reactive radiofrequency (RF) sputtering technique and then annealed at 900°C in pure O ₂ ambient for 1 h. The fabricated ZnO ultraviolet (UV) detector demonstrated a high responsivity of 2069 A/W when biased at 5 V, which could be attributed to the influence of the annealing process in pure O ₂ ambient. The response time measurement showed a rise time (10-90%) of 45.1 ns and a decay time (1 - 1/e) of 541 μs.